1) Diet in modern times is a challenge because our bodies are designed for simple basic foods.  With processed and bio-engineered and processed food, leached soils etc., our diets are anything but simple and are most certainly lacking is some basic necessities.   Here are some guidelines that can aid in your efforts:

• Maintain a balanced diet – approximately 30% Protein; 40% Carbohydrate; 30% Fat.   It is important to minimize refined carbohydrates and limit the amount of saturated fat and consume adequate amounts of 0mega 3 fats.  
• Don’t try to make a wholesale change.  Know where you are going and do it in small steps.
• Take a sensible regimen of vitamins. The idea here is that we give the body a variety of things in supplements we believe it needs.  The foundation of that effort is a good multiple vitamin.  Like a cafeteria, the body will take what it needs and eliminate what it doesn’t need in body waste.  In addition there are specific needs to be addressed that may not be met by a multiple vitamin.  It may be necessary to supplement above and beyond the multiple vitamin.

2) The expression "stress kills" is more true than we might give credit.  Stress, in addition to causing the body to secrete cortisol, causes the body to use/burn/leach substances critical to good health.   Supplementation replaces those substances.